The invention relates to a device for adjustment of universal joint shafts, such as the universal joint shafts of automobile drive trains.
For absorption of the position fluctuation of the universal joint shafts, determined by the axle kinematics of vehicles, as well as for compensation of construction tolerances, it is necessary to provide a torque-transmitting connection of the universal joint shafts with joints wherein a displacement of the universal joint shafts takes place. This connection can be arranged on the side of the differential and/or on the wheel side, depending on the drive mechanism (front-wheel, rear-wheel, four-wheel drive). In this connection, synchronizing slide joints are known which, by way of an appropriate cage, can absorb the displacement of the universal joint shaft and transverse movements of the unit. In extreme instances in which more extensive displacements of the universal joint shafts and related components, such as the differential, occur, the slide joints run against a stop, which is disadvantageous and leads to jamming and canting at the universal joint shaft as well as at the bearings.
In many cases, the displacement path is designed so short that displacements occurring additionally due to construction tolerances can no longer be compensated. However, expensive adaptation methods are known to provide adequate displacement capacity of the universal joint shaft and to ensure flawless functioning. In some such methods, the drive assembly is adjusted after construction in a cumbersome procedure. In other such methods the length of the universal joint shaft is adapted by means of spacer disks.
It is an object of the invention to provide a universal joint shaft which makes subsequent adjustment and adaptation unnecessary.
According to the invention, self-alignment of a universal joint with respect to its universal joint shaft axis takes place on account of a frictional coupling element inserted between hub and shaft. Additional manual readjustments of the joint and shaft are no longer required. Since the retaining force of the frictional coupling element is selected to be larger than the maximally occurring displacement force in the joint when the side joint is positioned between two end stops, a relative shifting of the shaft with respect to the hub is not possible after the universal joint shaft has been aligned, so that the operational displacements are absorbed exclusively in the joint. However, a displacement of the universal joint hub on the shaft is possible as soon as the joint is in abutting position.
On account of the arrangement of a frictional coupling element with a defined retaining force on the universal joint shaft, in accordance with this invention, neither the shaft nor the assembly needs to be adjusted during the building of a vehicle incorporating the universal joint. An automatic adjustment of the shaft, once it has taken place, remains preserved for future driving operation on account of the design of the retaining force.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for purposes of illustration only, embodiments in accordance with the present invention.